1. Field of the Invention
The present invention relates to communication systems. More specifically, the present invention relates to systems for switching feeds of a multiple beam antenna (MBA).
While the invention is described herein with reference to an illustrative embodiment for a particular application, the invention is not limited thereto. Those of ordinary skill in the art will recognize additional modifications, applications and embodiments within the scope of the invention.
2. Description of the Related Art
The utility of multiple beam antennas in addressing the ever increasing demands on communications payloads is well recognized. Multiple beam antennas (MBAs) are capable of providing plural agile beams for reception and/or transmission. The MBA may consist of a single reflector with multiple feeds or a phased array of feed horns. In either case, the feeds are selectively switched to effectuate beam selection and/or beam steering.
It has been noted that during the switching of feeds, switching transients may occur which may cause a momentary interruption of the communication link. In the case of a coherent receiver, that is, one utilizing a phase modulation scheme, a phase discontinuity may occur during switching. This would result in a loss of phase lock. As phase reqcquisition requires a finite amount of time, a glitch or momentary loss of data may result. It will be readily apparent that such a loss of data would be at least undesirable in most applications and of severe adverse consequences in some applications. There is therefore a need in the art for an improved switching system for coherent multiple beam antennas.